Piston grinders



J n 1953 H. E. BALSIGER ET AL 2,

PISTON GRINDERS Filed Dec. 2. 1954 5 Sheets-Sheet 1 INVENTOR llnkow LAMS/GER BY WILL AM 5. HA .PEL

QLQ /ZJ,

ORNEY June 17, 1958 H. E. BALSIGER ET AL 2,833,884

PISTON GRINDERS Filed Dec. 2, 1954 5 Sheets-Sheet 2 INVENTOR HAROLD E. BAN/GER BY WILLIAM E. f/APFEL ORNEY June 17, 1958 H. E. BALSIGER ETAL 2,838,884

PISTON GRINDERS Filed Dec. 2, 1954 v s Sheets-Sheet s INVENTOR hmma E saw/sale BY WIL IQ E,fi/APPEL ATTORNEY PISTON GRIN DERS Application December 2, 1954, Serial No. 472,579

14 Claims. (Cl. 51--101) This invention relates to machines for grinding pistons for internal combustion engines and particularly to means for automatically feeding pistons into operative position in a grinding machine and for locating and supporting them therein in a predetermined angular position.

When internal combustion'engine pistons were made cylindrical in shape, it was a comparatively simple operation to provide automatic means for introducing them between the headstock and footstock of a machine and then performing a grinding operation on the cylindrical surface thereof. However, since non-cylindrical pistons have come into general use, the problem of automatically loading and grin-ding them has introduced a secondary problem, namely that of placing the work piece in proper angular relation'to the driving means so that elliptical,

or any other non-cylindrical form, will be ground in proper angular relation to the piston structure.

United States Patent guide member 63 for engaging the head of said piston;

It is therefore an object of this invention'to provide means, for automatically placing pistons in a grinding machine in a predetermined angular position.

A further object is to provide a chute in which the piston is held in a predetermined angular position before it goes into the machine.

A further object is to provide a discharge opening which permits the ejection of a finished work piece but which may be partially closed to support the movement of an unground work piece into the machine.

A further object is to provide means whereby the V footstock moves toward the work far enough to place the support in the dischargeopening during loading and thereafter continues to move in the same direction to engage the'work piece and shift it axially into engagement with the work driving means. 7

A further object is to provide an escapement mechanism to advance individual work pieces in timed relation with the operation of other parts of the machine.

A further object is to provide means for automatically controlling the loading, grinding and ejection of work pieces.

In the drawings, Figure 1 is a partial front sectional elevation showing the relative positions of the work piece, footstock center and driving means as the work piece enters the machine and before it has been shifted axially into engagement with the driving-means.

Figure 2 is a sectional front elevation of the footstock.

Figure 3 is. an end view showing the work loading chute as mounted on the machine and also the escapement apparatusfor controlling the movement of the ,ably mounted in work drive member 21.

wheel 12. Said work has a headstock spindle 17 I0- tatably mounted in a conventional headstock (not shown). The method of supporting member 11 for oscillation is shown along with other structure not shown herein, in application S. N. 169,682 filed June 22, 1950 and now abandoned. The particular work piece 15 used for the purpose of illustration has a tapered or relieved skirt 18 which is used in this instance to engage a recess 19 in the ejectingmember 20. Said ejecting member is slid- Said work drive member has a pair of oppositely positioned driving pins 22 for engaging corresponding openings in the work piece 15. Draw rod 25 is attached to said driving mem-.

her and extends to the left through said headstock to an ejecting cylinder 26. Said cylinder has a piston 27 slidably mounted therein. Said piston 27 engages a rod 30 slidably supported in one end of said cylinder which in turn engages draw rod 25. A collar 35 is mounted on the end of rod 25 and hasa bevelled surface 36'for engaging and operating a limit switch 168. Rod 25 is urged to the left by a spring 28. The means for rotating the work piece 15 includes a motor M connected by a belt to pulley 86 onheadstock spindle 17.

The means for conducting work pieces into the grinding machine consists of a chute 60 having spaced guide members 61 and 62 for receiving the relieved skirt portion of the work piece 15 and an oppositely positioned The guide members 61 and 62 are in alignment with recess 19in ejector Ztlwhen said ejector is in the angular position shown in Figure 3. The width of said recess is the same as the spacing between the guide members 61 and 62. The movement of the Work in the chute is controlled by a pair of index fingers 68 and73 spaced alongthe chute at approximately the diameter of the work piece. piston 66 slidably mounted in cylinder 65. Afspring. 67 holds. said finger in chute blocking position. The lower index finger 73'is attached to a piston 71 incylinder 70;

, Finger 73 is held in chute blocking position by spring 72. .A resilient stop member 23 locates the work piece in approximate position to be engaged by the footstock center 16 and the driving pins 22. After a work piece has been ground, it is discharged by gravity into chute 80.

The means for'stopping rotation of the workpieceuwith the recess 19in alignment with the trackmembers 61 and 62 is disclosed in Patent 2,155,681, granted April 25, 1939.

Footstock center 16 is mounted in a footstock spindle 40 which in turn is slidably mounted in a footstock housing-41j Attached to said spindle is a member 42 which extends in advance of the spindle and has. a track member 43 for supporting the work piece as it moves out of a chute 60 into position to be engaged by the driving member 21 and footstock center 16. The endwisemovernent of spindle 40 is effected by .a piston 45 slidably mounted in a cylinder 46 attached to housing 41. A connecting rod 47 connects piston 45 with one end of footstock spindle 4t). Said piston rod has mounted .thereon a collar 48 slidably mounted in the cylindrical bore 49 in spindle 40.

A spring Stl-betwen collar 49 and a second collar 51 at the other end of the bore provide a yielding connection between piston 55 and spindle.40. 7

On the top of housing 41 and parallel with said spin-- dle is a shaft 55 slidably mounted in bushings 56 and urged to the leftby. a spring 57. One end of spring 57 bears against one of said bushings and the other end against a collar 59 which is pinned to said shaft. At the leftencl of saidrod is a guide member 58 which is suspended theref rom' into the path'of the footstock center 16.

The upper index finger 63 is attached to a An opening in member 58 permits center 16 to pass therethrough to engage the work piece. The normal position of member 58, as determined by spring 57 is that shown in Figures 1 and 2 in which it serves as a guide and locating means for the work piece as it is introduced into the machine. A shield 4 attached to the front end of spindle 41) serves to engage collar 59 to shift shaft 55 to actuate limit switch LS169.

Fluid under pressure for actuating the various hydraulic mechanisms is supplied by a pump 90 through a main pressure conduit 91. Line 91 is connected through restriction 92 to a pressure line 93 leading to the left end of the ejector cylinder 26. Line 91 is connected through restriction 94 and line 95 with the right end of footstock cylinder 46. The restrictions 92 and 94 provide a constant pressure less than pump pressure in the head ends of the ejector and footstock cylinders so long as valves 169a and 163:: remain in central position. Lines 93 and 95 may be connected with higher pressure or with exhaust through valves 160a or 163a respectively. 7

' Operation Closing the cycle start switch 190 completes a circuit through the cycle stop switch 101 to CR3. CR3-1 closes to complete a circuit from L1 through the cycle stop switch to provide a holding circuit. In this description, the number after the CR number identifies the relay contact. The letters NC and NO indicate that a switch or relay is normally closed or normally opened. CR3-1 completes another circuit through Lla and normally closed LS174 and normally closed CR19-1 to energize CR5. CR3 remains energized from cycle to cycle until stop switch 101 is opened. It makes available a secondary source of energy Lla which is fed from L1 through CR3-1. CR1 initiates operation of the ejecting mechanism after which the ejector and footstock are reset to loading position. With the reduced pressure at the head end of the ejector and footstock cylinders, the extent of the reset movement is determined by the intermediate ports 130 in the footstock cylinder and 140 in the ejector cylinder which serve to provide a restricted escape of the actuating fluid in each of said cylinders while the ejector and footstock are in position to receive an unground workpiece.

Loading-When the footstock center 16 is moved into this position by movement of piston 45 to the right, track 43 is located to block the discharge chute 80. LS167 closes as it is released by the footstock spindle 40, completing a circuit through normally closed CR19-3 to energize timer TR2. TR2 1 closes immediately, completing the circuit through CR-2 to valve solenoid 159 directing fluid under pressure to withdraw the lower indexing finger 73 and permit a work piece to slide out of chute 60 along track 43 into position to be picked up by the footstock center 16. After an interval suflicient to permit this movement of the work, TR2-2 closes, energizing CRIS and opening CRIS-1 and CRIS-2.

Opening CR15-2 de-energizes valve solenoid 159 permitting the valve 159a to beshifted to the left to connect the lower index cylinder 70 to exhaust, and resetting index finger 73 in chute blocking position. Opening CRIS-1 de-energizes valve solenoid 165 directing fluid under pressure to the intermediate port 130 incylinder 46 to continue the movement of the footstock to theleft. This movement of the footstock pushes the work piece 15 into engagement with the driving pins 22 and forces the ejector 29 to the left against the constant low pressure in the left end of cylinder 26. This movement also releases normally closed LS168 which energizes CR14.

connects line 140 with exhaust. The resulting drop in pressure in the ejector cylinder 26 eliminates the resistance to the footstock movement and has the effect of applying additional pressure to move the footstock to the left. This final movement of the footstock seats the work on the driving pins 22 and also releases normally closed LS166.

LS166 energizes CR19 through normally closed CR17-1 as soon as the footstock moves into grinding position. CR19-1 opens the circuit to CR5 and also the holding circuit to CR6 and resetting TR1.

Opening CR19-3 de-energizes and resets TR2. Closing CR192 energizes motor relay H to complete a circuit to work drive motor M starting the rotation of the Work. Closing CR19-4 completes a circuit to feed solenoid 154 shifting the feed valve 154a to direct fluid to the feed cylinder 110 to move piston 111 to the left and the grinding wheel 12 toward the work. As said wheel moves toward the work LS174 is opened by any suitable means such as a cam 200 on the feed piston rod 201. The circuit was previously opened by CR19-1 to deenergize CR6 and reset timer TR1.

When the feed cylinder reaches the end of its movement and the grinding operation is completed, pressure switch 152 is actuated as disclosed in Patent 2,678,521, granted May 18, 1954. Pressure switch 152 completes a circuit either immediately or after a predetermined interval to energize CR17, opening NC CR17-1 and deenergizing CR19.

CR19-5 closes completing a circuit from L1 through CR3-1, stop switch 100; and through normally closed 7 CR52 to energize valve solenoid 158 shifting the valve CR14-1 completes a circuit to energize ejector valve solenoid 161, shifting valve 160a to the left and connecting the left end of the ejector cylinder 26 to exhaust. At the same time, solenoid 162 is deenergized and valve 162a directs fluid to the right end of cylinder 26 and 158a to the left and directing fluid to the upper index cylinder 65 to withdraw the index finger 68 and permit a work piece to move forward against the lower index finger 73. De-energizing CR19 opens the circuit through CR19-4 to de-energize wheel feed solenoid 154 and cause the wheel to be withdrawn from grinding position. This movement of the wheel base permits the closing of LS174 to complete a circuit from CR3-1 through CR191 and energize CR5 thus opening CR5-2 immediately after the operation of valve solenoid 158, de-energizing said solenoid and resetting the upper index finger 68 to chute blocking position.

When CR19 is de-energized CR19-2 opens, de-energizing motor relay H and stopping work drive motor M. Said motor is stopped so that the pins 22 on the headstock and recess 19 in member 20 are in a predetermined angular position for engaging the next work piece.

Closing CR5-1 energizes valve solenoids 160, 162, 163 and 165.

Solenoids 160 and 162 are energized from CR5-1 through normally closed CR6-1. Solenoid 163 is energized from CR5-1 through normally closed CR122. Valve solenoid is energized from CR5-1 through normally closed CRIS-1.

Ejeczz'0n.Solenoid 161) shifts ejector valve to the right directing fluid under, pressure to the left end of the ejector cylinder and shifting the ejector 20 to the right to disengage the work piece 15 from driving pins 22.

Valve solenoid 162 shifts the ejector reset valve 162a to the right connecting the right end of the ejector cylinder 26 to exhaust.

Valve solenoid 163 shifts valve 163a to the right and connects the right end of the footstock cylinder to exhaust. Valve solenoid 165 shifts the valve 165a to the left directing fluid under pressure to the left end of the footstock cylinder 46 to shift the piston 45 and the footstock center 16 to the right.

The ejector pushes the Work piece off the driving pins and holds it in engagement with the footstock center 16 as said center is withdrawn. The footstock piston 45 is made to move at a slower rate than the ejector piston 27 so that a workpiece is gripped between the ejector member and the footstock center. This may be accomplished in anumber of ways. In this case, the footstock piston is designed to exert a predetermined force to hold the work against tize headstock. The ejector piston is made smaller than the footstock piston so that with the same volume of fiuid supplied to each, the footstock will tend to move more slowly than the ejector and the workpiece will be supported between these members as long as this condition exists. After the ejector has reached the end of its stroke, the footstock continues to withdraw and the workpiece is held between the ejector and guide member 58. As' the footstock continues to withdraw, shield 44 which is attached to the end of footstock spindle 40, moves with'it and engages a collar 59 on shaft 55 moving said shaft to the right against spring 57 until it engages and actuates LS169. Guide member 58 moves with shaft 55 to release workpiece 15. When the footstock center moves to the right, track member 43 which is attached to the footstock is shifted to a position in which it will not interfere with the discharge of a finished workpiece.

LS'169, actuated by shaft 55 through withdrawal of the footstock, completes a circuit to energize CR6. CR6-2 holds the relay energized through normally closed LS174 and normally closed CR19-1. LS169 also completes a circuit to energize TR1.

Energizing CR6 opens CR6-1 to de-energize solenoids 160 and 162. De-energizing valve solenoid 160 permits the valve 160a to move to load position in which it blocks the exhaust from ejector cylinder 26. De-energizing solenoid 162 permits the valve 162a to move to the left connecting the right hand end of cylinder 26 with pressure and the intermediate port to exhaust. The ejector is thus withdrawn to loading position in which piston 27 is stopped at the intermediate port 140 by covering said port and preventing the passage of exhaust fluid therethrough and by the makeup pressure in the head end of the cylinder. This movement of the ejector with the above described retraction of guide 58 releases the workpiece which is discharged by gravity through chute 80. TR1 which was energized when LS169 was closed to allow time for the removal of the finished workpiece, times out, energizing CR12, opening CR12-2 and closing CR121.

Closing CR12-1 energizes footstock valve solenoid 164 shifting the valve 163a to the left and directing pressure to the head end of the footstock cylinder 46. Opening CR12-2 de-energizes footstock solenoid 163 to permit the above described movement of the valve 163a by solenoid 164. The footstock piston 45 moves to loading position at which point the fluid in the left end of cylinder 46 is permitted to escape through the footstock reset valve 165a so that the piston 45 stops after opening the port 130 leading to said valve. The loading operation described above is repeated at this point and a new grinding cycle initiated.

We claim:

1. In a grinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, hydraulic means including pistons and cylinders for actuating said footstock and said ejector, means for exerting a relatively low pressure in the head end of each said cylinders to hold said ejector and the footstock center toward one another to hold a workpiece therebetween, means including control valves to direct fluid under pressure to move both of said pistons to carry a workpiece to discharge position, means to cause said footstock piston to move at a slower rate than said ejector piston whereby to resist the movement of said ejector and thus exert suflicient force on the workpiece to support said workpiece during said movement.

2. In a grinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, hydraulic means including pistons and cylinders for actuating said footstock and said ejector, means for exerting a relatively low pressure in the head end of each of said cylinders to urge said ejector and the footstock center toward one another to hold a workpiece therebetween and means including a valve to increase the pressure on the head end of one of said cylinders to urge the workpiece against the lower pressure on the other of said cylinders.

3. In a grinding machine, a work carriage, a head stock and a footstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, means on said headstock for positively engaging and driving a workpiece, hydraulic means including a piston and cylinder for actuating said footstock and said ejector, means for exerting a relatively low pressure in the head end of each of said cylinders to urge said ejector and the footstock center toward one another, and means including a valve operable thereafter to increase the pressure on the head end of the footstock cylinder to urge a workpiece tothe left against the lower pressure on the ejector cylinder to move said workpiece into operative engagement with said driving means.

4. In a grinding machine, a work carriage, a head stock and a footstock on said carriage for rotatably supporting a workpiece, means on said headstock for engaging and driving a workpiece including a pair of driving pins, means for introducing a workpiece laterally into said machine, means for actuating said footstock to urge said workpiece into operative engagement with said driving pins, timing means, means actuated by movement of said footstock into loading position to actuate said timing means for delaying final action of said footstock until said workpiece is in position to be engaged by said footstock.

5. In a machine for grinding pistons, a chute for conducting said pistons into operative position on the machine, and guide means on said chute for engaging opposite sides of certain portions of said pistons to hold same in predetermined angular position whereby said pistons are placed in the machine in said predetermined angular position.

6. In a grinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, h draulic means including pistons and cylinders for actuating said footstock and said ejector, a supply of fluid under pressure for said hydraulic means, means for controlling said supply of fluid under pressure to said cylinders for shifting said ejector and footstock simultaneously in one direction for unloading, a supply chute for directing unground workpieces into the machine, a discharge chute at the lower end of said supply chute, a track member for providing a supporting surface for loading a workpiece into the machine, said track member also preventing premature discharge of an unground workpiece, said track member being movable with the footstock, means to continue the withdrawal movement of the footstock after said ejector has completed its movement, said continued movement of said footstock being eifective to remove said track member from the entrance to said discharge chute whereby to permit the discharge of a ground workpiece.

7. In a grinding machine for grinding pistons, a work supporting member, a headstock mounted thereon for rotating a work piece, a chute for conducting pistons into operative relation with said headstock, vertically spaced guide means on said chute for engaging portions of said pistons to hold said pistons in a predetermined angular position, correspondingly spaced guide means on said headstock and means for stopping said headstock with said guide means in alignment with the guide means on said chute.

8. In agrinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting a work piece, an ejector in said headstock, hy-

draulic means including pistons and cylinders for actuating said footstoek and said ejector, a hydraulic wheel feed motor, asupply of fluid under pressure for actuating said hydraulic means, means responsive to the withdrawal movement of said wheel feed means for actuating said ejector and said footstock to move a finished work piece to discharge position, means responsive to the withdrawal movement of said footstock, to release the work piece in discharge position, means also actuated by said footstock moving to discharge position for returning the ejector to loading position, means operable after a predetermined interval for returning the footstock to loading position, means responsive to the movement of the footstock to loading position for releasing a work piece to move into operative relation with the headstock and footstock,.and after a predetermined interval to continue the movement of the footstock and ejector to place the work piece in grinding position, and means responsive to the movement of the footstock into grinding position to initiate.

operation of said wheel feed means.

9. In a grinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting-a workpiece, an ejector in said headstock, hydraulic means i including pistons and cylinders for actuating said footstock and said ejector, a supply of fluid under pressure for actuating said hydraulic means, means for controllingisaid 1 1 supply of fluid under pressure to said cylinderstor' shifting said ejector and footstock simultaneously in one di? rection to carry a workpiece to an unloading position,

means to continue said movement of said footstock whereby to release said workpiece after said ejector has compiece as it enters the machine, and means responsive to said continued movement of said footstock for removing said bridge from the opening of said discharge chute to--- permit the discharge of a finished workpiece."

10. In a grinding machine, a work carriage, a headstock and a rootstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, hy-

draulic means including pistons and cylinders for aetu-'" ating said footstock and said ejector, means for moving said ejector and said footstock toward one another to engage and support a workpiece and means to stop the movement of said ejector and said footstock short. of engagement with the work to permit the movement of the work into position between said members including draulic means including pistons and cylinders for actu-- ating said footstock and said ejector, means for exerting a relatively low pressure at all times during a grindingcycle in the head end of each cylinder to urge said ejector and footstoek center toward one another, means to limit said movementcornprising an intermediate port in each of said cylinders, which when uncovered by the pistons, provides a restricted opening for the actuating-fluid to escape and thus stop the center and ejector in axially spaced relation sufficient to permit the reception of an unground workpiece.

13. In a grinding machine, a work carriage,-a headstock and a footstock on said carriage for rotatably sup porting a workpiece, an ejector in said headstock, means on said headstock for positively engaging and driving a workpiece, means for actuating said vfootstoek and said ejector including a piston and a cylinder for each of said members, means for exerting a relatively low pressure in the head end of each of said cylinders to urge said ejector and footstock center toward one another, means including valves actuated in timed relation and operable to increase the pressure on the head end of the footstock cylinder to urge a workpiece to the left against the lower pressure of the ejector cylinder to move said workpiece into operative engagement with said driving means and means for connecting said ejector cylinder to an exhaust line whereby to produce, in eflect, an increase in the force 'exerted by said footstock to seat said driving means firmly in said workpiece.

14. In a grinding machine, a work carriage, a footstock and a headstock on said work carriage for rotatably supporting aiworkpiece, an ejector in said headstock,

hydraulic means including pistons and cylinders for actuating said footstock and said ejector, a pump for supplying fluid underpressure to said cylinders, means including conduits directly connecting said pump with each of intermediate ports in said cylinders, control valves, con- 1 nections from said ports to said control valves, said valves being positioned to permit the discharge of said fluid under pressure after said pistons uncover said intermediate ports, and means for thereafter shifting one of said valves to prevent discharge of fluid under pressure from one of said intermediate ports whereby to continue the movement of the member controlled by said valve to engage a workpiece.

11. In a grinding machine, a work carriage, a headstock and a footstock on said carriage for rotatably supporting a workpiece, an ejector in said headstock, hydraulic means including pistons and cylinders for actuating said footstock and said ejector, means for moving said ejector and said footstock simultaneously in one direction to carry a workpiece from grindnig position to discharge said cylinders for exerting a relatively low pressure at all times during a grinding cycle in the head end of eachcylinder to urge said ejector and footstock center toward one another, a valve connected to each of said conduits for alternately connecting said conduits with higher pressure or with exhaust, and means for actuating said valves in a predetermined timed relation.

References Cited in the file of this patent UNITED STATES PATENTS 826,694 Shirley July 24, 1906 1,841,988 Smith Jan. 19, 1932 1,946,429 Smith Feb. 6, 1934 1,970,023 Schroeder Aug. 14, 1934 1,997,551 Romaine Apr. 9, 1935 2,117,917 Silven May 17, 1938 2,678,521 Flohr May 18, 1954 

